"ArgumentNullException" thrown when clicking the "add" footer button of ListView which itemsSource is a list of value type

Unity: UI Toolkit Controls

2023.2.X

2023.1.X

2022.2.X

2021.3.X

2023.3.X

2022.1.X

No port needed for 2023.3, this fix landed before, in 2023.2.

We no longer backport UI Toolkit fixes to 2022.1.X. The issue will be fixed in 2022.2.X instead.

How to reproduce:

Expected results: No errors thrown
Actual results: "ArgumentNullException: Value cannot be null." thrown in the Console window

Reproducible with: 2021.3.17f1, 2022.1.24f1, 2022.2.3f1, 2023.1.0a26
Could not test with: 2020.3.44f1 (compilation errors in the Console window)

Reproducible on: Windows 10